Electronic detergent dispensing system

ABSTRACT

A detergent dispensing system for sequentially and automatically injecting various liquid products (e.g., detergents, fabric conditioners, neutralizers, etc.) into a laundry washing machine. Each liquid product is independently connected to a venturiaspirator positioned within separate carrier fluid conduits (e.g. water conduits) and product is drawn into the respective carrier fluid conduits upon passage of carrier fluid therethrough. Electrical control means, including electrical timing apparatus, triggered by a signalling device synchronized with the machine washing cycle selectively actuates and deactuates a solenoidoperated valve positioned upstream of each venturi-aspirator so as to allow injection into the carrier fluid of a predetermined quantity of each liquid product at the desired point in the machine cycle.

United States Patent Kleimola et al. [45 M 6, 1975 [54] ELECTRONICDETERGENT DISPENSING 3,301,022 l/l967 Low 68/[7 R X SYSTEM 3.5l0,0265/1970 Wright 68/ 17 R X [75] Inventors: David L. Kleimola; Marcus I.Primary Examiner Bm L wilhite Nysmen both Paul; AssistantExaminer-Philip R. Coe Nystuen Bloommgton' of Attorney, Agent, orFirmMerchant, Gould, Smith & [7 3] Assignee: Economics Laboratory, Inc.,St.

Paul, Minn. 22 Filed: Feb. 23, 1973 {57] ABSTRACT A detergent dispensingsystem for sequentially and au- [2l] Appl. No.: 335,136 tomaticallyinjecting various liquid products (e.g.. de-

R ht d Us, A li ti Data tergents, fabric conditioners, neutralizers,etc.) into a [62] Division of Sen No. 210 669 Dec. 22 971 laundrywashing machine. Each liquid product is indeabandoned pendentlyconnected to a venturi-aspirator positioned within separate carrierfluid conduits (e.g. water con- 52 us. C| 68/12 68/" 68/207; duits) andproduct is drawn into the respective carrier 134/95; 134/100 fluidconduits upon passage of carrier fluid there- 51 Int. D06f 33/02; D06f39/02 thmugh- Electrical Comm means, including electrical 53 Field ofSearch 68/12 R, 11 R, 207; timing apparatus, triggered by a signallingdevice y ]37/624 18; 222/701 76, 134/58 D 95, chronized with the machinewashing cycle selectively 100, 101 actuates and deactuates asolenoid-operated valve positioned upstream of each venturi-aspirator soas to 5 References Cited allow injection into the carrier fluid of apredeter- UNITED STATES PATENTS mined quantity of each liquid product atthe desired point in the machine cycle.

2 Claims, 3 Drawing Figures ELECTRONIC DETERGENT DISPENSING SYSTEM Thisis a division of application Ser. No. 2l0,669, filed on Dec. 22, l97l,and now abandoned, of David L. Kleimola et al. for Electronic DetergentDispensing System".

BACKGROUND OF THE INVENTION 1. Field of the Invention The presentinvention pertains to a system for automatically dispensingpredetermined quantities of a plurality of liquid products.

2. Description of the Prior Art It is frequently necessary toselectively dispense a plurality of fluid products into the carrierfluid utilized in various operations and processes. For example, a widevariety of liquid detergents, laundry soaps, iron control agents.neutralizers, etc., are frequently injected into the water utilized inmachine clothes washers, dishwaters, etc. This is particularly true forthe laundry operation in large commercial institutions (e.g., hotels,restaurants. hospitals, etc.). Since entirely manual dispensing of thevarious laundry products is uneconomical and unreliable in a commercialenvironment, numerous attempts have been made to provide eithersemi-automatic or automatic dispensing of the liquid products.

The presently available semi-automatic dispensing units operate on aload-by-load basis. The amount of each liquid product (or powderedproduct) necessary to provide the desired cleansing action, neutralizingaction. etc., for a single laundry load is measured out and positionedwithin separate receptacles associated with the laundry machine. Inresponse to an electrical signal generated by the machine, wash water isselectively channeled through one or more of the receptacles at theappropriate time during the machine washing cycle and the product isinjected into the washer. The product receptacles are then refilled forthe next load. While such semi-automatic apparatus is generally moredependable than entirely manual dispensing, this type of apparatus isstill subject to human error in measuring the proper amount of productfor each load as well as the proper placement of the products (i.e.,placement of each product within the correct receptacle).

The automatic dispensing unit eliminates the necessity of mannuallymeasuring the laundry products and manually adding the measured productsto the machine at the completion of each washing cycle. However, thepresently available apparatus is exceedingly expensive and does notprovide an accurate dispensing as is desirable. For instance, onecommercially available unit utilizes the conventional formula chartcontrol so as to electrically actuate and deactuate a plurality ofpressurized containers containing liquid products and a plurality ofproduct valves to allow selective dispensing of the liquid products. Toaccomplish this, a hole is cut into the formula chart (i.e. a plastictape) at an appropriate position and. during the passage of this holepast a pressure sensitive (vacuum) switch, the pressurized tanks areactivated to allow dispensing of one or more of the liquid products.However, to dispense the desired amount of each liquid productnecessitates extreme accurateness in the cutting of the holes within theformula chart and in the method of controlling and maintaining thedesired pressure requirements. The proper control of these variables hasproven exceedingly difficult and, consequently, this type of apparatushas not provided as accurate dispensing as is desirable. A furtherdisadvantage of this type of apparatus is the need to transfer thepowdered and/or liquid products from their shipping containers intoseparate high pressure containers for dilution with water and subsequentinjection into the laundry machine. Thus, while apparatus is presentlyavailable which incorporates the wash cycle and product dispensingsystems into one system, this apparatus is exceedingly expensive andgenerally unreliable. Alternative injection timing apparatus, such as acam-operated timer, is neither dependable nor readily adjustable.

SUMMARY OF THE INVENTION Our invention utilizes a signal generatingdevice for generating electrical triggering signals having apredetermined duration. These triggering signals are received byelectric control means which, upon receiving the triggering signal,selectively operates one of a plurality of product injection means toallow injection of a particular product into a carrier fluid. Thecontrol means includes timing apparatus for generating a control signalto deactuate the injection means prior to the termination of thetriggering signal. The dispensing system finds a highly desirableapplication in conjunction with institutional laundry machines. In thepreferred embodiment, a plurality of liquid product containers are eachindependently connected to a venturiaspirator positioned within separateconduits for providing wash water to the laundry machine. The electricalcontrol apparatus operates a solenoid-operated valve positioned upstreamof each of the venturiaspirators thereby controlling the injection ofthe liquid products through the respective venturi-aspirators and intothe water conduit.

The present invention provides several significant advantages which arenot found in the liquid detergent dispensing units heretofore available.First, it is entirely automatic, yet highly accurate in operation andinexpensive to construct. The unrealiability and inaccurateness of theprior art dispensing units is substantially overcome by the electricaltiming apparatus for timing the period during which each liquid productis injected into the laundry machine. This timing apparatus eliminatesthe necessity of relying on the duration of a signal generated by thelaundry machine (e.g. by an electronic formula chart) to regulateproduct injection. Rather, by properly calibrating the adjustable timingapparatus, highly accurate and dependable dispensing of a plurality ofliquid detergents can be provided independent of the duration of theinitial triggering signal. For instance, utilizing the present inventionthe timing interval for injecting products is regulatable and repeatablewell within one second intervals, whereas the timing interval of priorart systems typically varies from about t 3 seconds to about 1' 8seconds. Additionally, the reliability of our detergent system is notaffected by contaminants (e.g. lint, burrs. etc.) which frequentlyinterfere with the reliable operation of the prior art systems. This isa particularly important feature when the total product feed time isrelatively short (e.g. 3 seconds). Finally. the utilization ofventuri-aspirators in the preferred embodiment to inject the productinto the water conduit eliminates the need to utilize relatively costlyhigh pressure apparatus for effecting dispensing of the various liquidproducts into the washing machine. It has also been found that by theproper choice of the venturi orifice size as well as the setting for theelectrical timing apparatus, highly precise regulation of the quantitiesof liquid products injected into a carrier fluid can be achieved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a diagrammatic view of thepresent liquid detergent dispensing system;

FIG. 2 is an enlarged diagrammatic view of the mechanical portion of theliquid product injection apparatus utilized in the dispensing systemillustrated in FIG. I; and

FIG. 3 is a schematic diagram of the electronic circuitry utilized tooperate the valving means shown in FIG. 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to thedrawings and particularly to FIG. I, the numeral generally designatesthe system provided by the present invention for injecting a pluralityof liquid products into a washing machine 12. The illustrated washingmachine 12 is a laundry washing machine of the type commonly utilized invarious commercial institutions. It should be understood, however. thatthe term washing machine" is used herein to generally designatediswashing machines, laundry washing machines and similar batchprocessing apparatus. Furthermore, the present dispensing system canfind numerous additional applications in conjunction with variousapparatus and processes in which it is desired to sequentially inject aprecisely controlled amount of a plurality of liquid products.

As can be seen in FIG. I. the dispensing system 10 includes controlapparatus 14 having a mechanical por tion Na and an electrical portion14b. As described subsequently in greater detail, the control apparatus14 controls the injection of various liquid products (e.g. detergents.laundry soaps, stainremoving agents. fabric conditioners, neutralizers,iron control agents, etc.) into the laundry machine 12. As shown, thevarious liquid products are contained within suitable receptacles orcontainers ISa-lSe and conveyed to control apparatus 14 by liquidproduct conduits l6a-l6e, respectively. Preferably. conduits l6al6e areadapted for connecting directly to a bung hole in the respective one ofthe liquid product conduits receptacles ISa-lSe. This eliminates thenecessity of transferring each liquid product from the shippingcontainer to a container suitable for utilization during the dispensingoperation. As subsequently explained, the liquid product conduitsl6a-l6e are connected within the mechanical portion 14a of the controlapparatus I4 to conduit means l8 suitable for conducting a carrierliquid (e.g. water) therethrough. A plurality of conduits l9a-l9econnect the control apparatus I4 to the washing machine I2 forconducting therethrough mixtures of the various liquid products andliquid carrier. Finally, a trigger signal generating means is associatedwith the washing machine 12 and synchronized therewith so as to generateelectrical triggering signals at predetermined times dur ing the washingmachine cycle. The trigger signal generating device is electricallyconnected to the electrical portion 14b of control apparatus 14 byelectrical conduit means 22.

The mechanical portion 140 of control apparatus 14 can be bestappreciated with reference to FIG. 2. As

shown, the water conduit I8 has positioned therein a plurality ofelectrically actuated valve means 25a, 25b and 250. A pair of electricalterminals 26 and 27 are provided for electrically connecting each of thevalves 25a-2Sc to electrical control apparatus I4b so as to allowindependent actuation and deactuation of the respective valves. Thiscontrols the flow of water through the conduits l8a-l8c which areconnected to the downstream side of valves 25a-25c, respectively. Asiphon breaker 28a, 28b and 28c is positioned within each of the branchconduit l8a-l8c, respectively, so as to prevent liquid product fromentering the respective conduits I8a-l8c in the case of a negativepressure therein. Downstream of the siphon breaker 28a, the conduit 18aTs" or separates into a pair of conduits 19a and 19b. Similarly, theconduit 18c Ts or separates into a pair of conduits 19d and 19a. Thisallows injection of a greater number of liquid products or,alternatively, a greater amount of the same product. However, theconduits l8a-I8c can be connected to any number of conduits (e.g.conduit 18b is connected to a single conduit 19c) dependent on thenumber of liquids products which are to be independently andsimultaneously injected into washing machine 12. Finally, venturi meansin the form of venturi-aspirators 30a-30e are positioned within each ofthe conduits l9a-l9e, respectively. As shown, the venturi-aspirators30a-30e are connected to the liquid product conduits l6a-l6e,respectively, for drawing the various liquid products housed withincontainers lSa-lSe through the respective conduits l6a16e and injectingthe liquid product into the conduits -192 upon flow of the carrierliquid therethrough. The operational principle of venturiaspirators iswell known and need not be described in detail. In this same regard, thesize and drawing capacity of each of the venturies 30a-30e are notcritical to the present invention and the selection of appropriateventuri-aspirators and metering tips to provide the desired injectionrates is within the skill of the artisan. As will subsequently becomeapparent, valve means 25a-25c and venturi-aspirators 30a 30c function aselectrically actuated injection or pump means for allowing injection ofthe fluid products into the carrier fluid upon actuation thereof. Itshould be understood, however, that other types of injection means suchas a conventional electromechanical pump can be utilized in replace ofsolenoid valves 25a-25c and venturiaspirators 300-30e.

Electrical control apparatus 14b is provided to independently actuatethe control valves 25a-25c. The electrical apparatus 14b includesseparate circuitry for controlling each of the valves 25a-25c. One suchcircuit (e.g. for controlling valve 25a) is shown in FIG. 3 and isgenerally designated 35. Similar circuits (not shown) are provided forthe remaining two valves (i.e. valves 25!) and 250). These circuits aresimilar to the circuitry shown in FIG. 3 with the possible exception ofthe component values used therein.

As shown, the electrical circuitry 35 includes a pair of leads 40 and 41which are connected to the terminals 42a and 42b of trigger signalgenerator means 20. Positioned in series in lead 40 are a triac 43, anda terminal 47. Lead 41 is connected directly to a terminal 48. Theterminals 47 and 48 are connected to the terminals Z6 and 27 of valve25a by suitable electrical leads (not shown).

A PNP transistor 50 has its emitter 5l connected to the lead 40 througha potentiometer 52 and a resistor 53. The collector 54 of transistor 50is connected to the base of a NPN transistor 56 and a through acapacitor 57 to a lead 58. The lead 58 is connected through a diode 55to the lad 81. Diode 55 and series capacitor 59 provide rectificationand filtering of the a-c voltage between leads 40 and 4]. Thepotentiometer 52, resistor 53, transistor 50 and serves as aresistancecapacitance (RC) charging network for capacitor 57 in serieswith the RC network. The potential across capacitor 57 provides thefiring point for the transistor 56. The transistor 50 is a generallyconstant current device providing an essentially constant charging ratefor capacitor 57. This provides for a more linear time adjustment forthe firing of transistor 56.

The emitter 60 of transistor 56 is connected to the lead 58 through apair of resistors 61 and 62. The collector 63 of the transistor 56 isconnected to the base 64 of transistor 50 and to the lad 40 through aresistor 65. Collector 63 is also connected to the lead 58 through aresistor 66. The pair of resistors 61 and 62 provide the emitter biasfor the transistor 56. A silicon-controlled-rectifier (SCR) 70 has itsgate 7| connected between resistors 6] and 62. The anode 72 of SCR 70 isconnected through a resistor 73 to the lead 40 and through a pair ofresistors 74 and 75 to the lead 58. The cathode 76 of SCR 70 isconnected directly to the lead 58. A capacitor 78 shunts the emitter 72and collector 76 of SCR 70. The resistors 73, 74 and 75 function as avoltage divider network for providing the voltage to the base 79 of aNPN transistor 80. As shown, NPN transistor 80 has its base 79 connectedthrough a diode 82 to a junction point 84 between resistors 74 and 75.The emitter 88 of transistor 80 is connected directly to lead 58.Finally, the collector 89 of transistor 80 is connected through aresistor 90 to the gate 91 of the triac 43. The values of the resistors73, 74 and 75 (i.e. the voltage divider network) are chosen so that uponthe occurence of a triggering signal at terminals 42a and 42b. thetransistor 80 is switched to a conducting state and, consequently,biasing triac 43 to a conducting state. Thus, the triggering voltageoccurs at terminals 26 and 27 of valve 25a and thereby actuating thevalve 25a instantaneously with the occurence of the triggering signal atterminals 420 and 42b. As subsequently explained, the remainingcircuitry illustrated in FIG. 3 functions as a timing network to providea control signal for deactuating valve 250 prior to the termination ofthe tirggering signal at terminals 42a and 42b.

For a triggering signal of 24 volts magnitude, the following componentvalues have been utilized.

-Continued Resistors Value semlconductor components Type 43 AOIOOZ 502N4402 56 2N34l 7 2N506| 80 2N34l 7 The operation of the presentinvention can be described as follows. When it is desired to injectvarious liquid products into washing machine 12 at predetermined timesduring the machine cycle, the trigger signal generating means 20 issynchronized with the machine cycle so as to provide triggering signalsto electrical apparatus 14b which, in turn, transmits a control signalto the appropriate one(s) of the valves 25a-25c at the desired times.These triggering signals can be generated, for example, by cam-operatedswitches or the passage of a punched formula chart past properlypositioned Micro Switches or pressure-sensitive switches. However, forreasons which will subsequently become apparent, our invention is unlikethe dispenser units heretofore available in that the duration of thetriggering signal is no longer of critical importance, Rather, thelength of the injection period is independent of the duration of thetriggering signal.

Upon the occurence of a triggering signal at terminals 42a and 42b, thetransistor 80 is switched to a conducting state. This in turn biasestriac 43 into a conducting state resulting in an actuating or controlsignal appearing at terminals 26 and 27 of valve 25a. This signalactuates valve 250 allowing water to flow therethrough and into theconduits 18a. The passage of water through the venturi-aspirators 30aand 30h draws the liquid products within the respective receptaclesl5al5b through the conduits 16a and 16b and injects the products intothe carrier fluid flowing through the conduits 19a and 19b. The mixtureof liquid product and carrier fluid is then introduced into washingmachine 12 through the conduits I90 and 19b.

The occurence of a triggering signal at terminals 42a and 42b causes thecapacitor 57 to begin charging through the RC charging networkcomprising potentiometer 52, resistor 53, transistor 50. Upon thevoltage across capacitor 57 reaching the firing point of transistor 56(e.g. about 12 volts), the transistor 56 is switched to a conducingstate. This biases SCR 70 into a conducting state shunting resistors 74and and switching transistor to a non-conducting state. The charge heldby capacitor 78 adds to the output pulse of SCR 70 assuring the properswitching of transistor 80. Upon the switching of transistor 80 to anonconducting state, the triac 43 is switched to an of state and remainsin a non-conducting state so long as the triggering signal is present atterminals 420 and 42b. This deactuates the valve 250. Upon thetermination of the triggering signal from trigger signal operating means20, the electrical circuitry automatically resets itself.

Thus, it can be seen that by varying the resistance of potentiometer 52,the time required to charge capacitor, 57 for firing transistor 56 isalso varied. This allows ready adjustment of the time period duringwhich power is supplied to the valve 250 and, consequently. of the timeperiod during which liquid products are drawn into the conduits 19a and19b and carried along by the water flowing therethrough until injectedinto the washing machine 12. As can be readily appreciated. by theproper choice of component values and by adjustment of potentiometer 52,the time period during which liquid product is injected into machine 12is variable over the entire period of duration of the triggering signalfrom trigger signal generating means 20. While the maximum duration ofthe injection period in the de scribed embodiment is limited by theduration of the triggering signal, it should be understood that by useof conventional electrical components (eg holding coil relays) theinjection of products can be made to continue after the termination ofthe triggering signal. It should also be appreciated that it may bedesirable to choose different component values for the timing circuitryutilized to deactuate valves 25b and 25c than was the case for valve25a.

Since the present invention has been described in conjunction with apreferred embodiment thereof, numerous modifications thereto will bereadily apparent to the artisan. For example, as mentioned previously,numerous signal generating means can be utilized to provide properlytimed triggering signals synchronized with the machine cycle. Also,numerous design changes can be made to allow injection of a greater orlesser number of products as well as different quantities of eachproduct. This being the case, it is our intent to be limited solely bythe spirit and scope of the appended claims.

What is claimed is:

l. A system for supplying precisely controlled amounts of liquid productto a washing machine having a main water supply controlled in apredetermined machine cycle, comprising:

a. a carrier liquid conduit in addition to the main water supplyconnected to the washing machine, for conveying carrier liquid thereto;

b. electrically actuable valve means located in said carrier liquidconduit and effective when actuated to enable the continuous flow ofcarrier liquid to the machine therethrough;

c. venturi-aspirator means located in said carrier liquid conduit forconduction of the carrier liquid under the control of said valve means;

d. a receptacle for containing a liquid product to be injected into saidmachine;

a liquid product conduit connecting said receptacle to saidventuri-aspirator means so that upon flow of carrier liquid therethroughthe liquid product is drawn from said receptacle and injected into thecarrier liquid flow, whereby the amount of liquid product supplied tothe washing machine is deter mined by the duration of carrier liquidflow in the carrier liquid conduit;

f. a cycle controlling timing device associated with the washing machinefor providing an electrical triggering signal synchronized with a stepof the machine cycle; and

g. electrical control apparatus connected to receive said electricaltriggering signal from said cycle controlling timing device, includingan electrical timer connected to said valve means, and operative uponinitiation of said electrical triggering signal to produce first andsecond control signals spaced by a predetermined delay interval. saidapparatus including means actuating and maintaining actuated said valvemeans in response to said first control signal and deactuating saidvalve means in response to said second control signal, so that theamount of said liquid product supplied to said machine as a result ofeach triggering signal is a function of the duration of said delayinterval, regardless of further continuance of said triggering signal.

2. A system for supplying precisely controlled amounts of various liquidproducts to a washing machine having a main water supply controlled in apredetermined machine cycle, comprising:

a. means defining a plurality of carrier liquid conduits in addition tothe main water supply connected to the washing machine, for conveyingcarrier liquid thereto;

b electrically actuable valve means located in said carrier liquidconduits and severally effective when actuated to enable the continuousflow of carrier liquid to the machine therethrough;

c. venturi-aspirator means located in said carrier liquid conduitsdownstream from said valve means for conduction of the carrier liquidunder the control of said valve means;

d. a plurality of receptacles for containing different liquid productsto be injected into said machine; e. liquid product conduit meansconnecting each of said receptacles to a different one of saidventuriaspirator means so that upon flows of carrier liquid through theseveral venturi-aspirators the liquid products are drawn from saidreceptacles and injected into the carrier liquid flows, whereby theamount of each liquid product supplied to the washing machine isdetermined by the duration of carrier liquid flow in the carrier liquidconduit;

f. a cycle controlling timing device associated with the washing machinefor providing a sequence of distinguishable electrical triggeringsignals synchronized with the steps of the machine cycle;

g. electrical control apparatus connected to receive said electricaltriggering signals from said cycle controlling timing device, includingelectrical timers connected severally to the several valve means, eachof said timers being operative upon initiation of one only of saidtriggering signals to produce first and second control signals spaced bya predetermined delay interval, said apparatus including means actuatingand maintaining actuated the several valve means in response to theseveral first control signals and deactuating the several valve means inresponse to the several second control signals, so that the amount ofeach liquid product supplied to said machine as a result of a triggeringsignal is a function of the duration of the predetermined time delayinterval, regardless of further continuance of said triggering signal;and

h. means in each electrical timer for precisely adjusting the durationof the predetermined delay interval thereof.

1. A system for supplying precisely controlled amounts of liquid productto a washing machine having a main water Supply controlled in apredetermined machine cycle, comprising: a. a carrier liquid conduit inaddition to the main water supply connected to the washing machine, forconveying carrier liquid thereto; b. electrically actuable valve meanslocated in said carrier liquid conduit and effective when actuated toenable the continuous flow of carrier liquid to the machinetherethrough; c. venturi-aspirator means located in said carrier liquidconduit for conduction of the carrier liquid under the control of saidvalve means; d. a receptacle for containing a liquid product to beinjected into said machine; a liquid product conduit connecting saidreceptacle to said venturi-aspirator means so that upon flow of carrierliquid therethrough the liquid product is drawn from said receptacle andinjected into the carrier liquid flow, whereby the amount of liquidproduct supplied to the washing machine is determined by the duration ofcarrier liquid flow in the carrier liquid conduit; f. a cyclecontrolling timing device associated with the washing machine forproviding an electrical triggering signal synchronized with a step ofthe machine cycle; and g. electrical control apparatus connected toreceive said electrical triggering signal from said cycle controllingtiming device, including an electrical timer connected to said valvemeans, and operative upon initiation of said electrical triggeringsignal to produce first and second control signals spaced by apredetermined delay interval, said apparatus including means actuatingand maintaining actuated said valve means in response to said firstcontrol signal and deactuating said valve means in response to saidsecond control signal, so that the amount of said liquid productsupplied to said machine as a result of each triggering signal is afunction of the duration of said delay interval, regardless of furthercontinuance of said triggering signal.
 2. A system for supplyingprecisely controlled amounts of various liquid products to a washingmachine having a main water supply controlled in a predetermined machinecycle, comprising: a. means defining a plurality of carrier liquidconduits in addition to the main water supply connected to the washingmachine, for conveying carrier liquid thereto; b. electrically actuablevalve means located in said carrier liquid conduits and severallyeffective when actuated to enable the continuous flow of carrier liquidto the machine therethrough; c. venturi-aspirator means located in saidcarrier liquid conduits downstream from said valve means for conductionof the carrier liquid under the control of said valve means; d. aplurality of receptacles for containing different liquid products to beinjected into said machine; e. liquid product conduit means connectingeach of said receptacles to a different one of said venturi-aspiratormeans so that upon flows of carrier liquid through the severalventuri-aspirators the liquid products are drawn from said receptaclesand injected into the carrier liquid flows, whereby the amount of eachliquid product supplied to the washing machine is determined by theduration of carrier liquid flow in the carrier liquid conduit; f. acycle controlling timing device associated with the washing machine forproviding a sequence of distinguishable electrical triggering signalssynchronized with the steps of the machine cycle; g. electrical controlapparatus connected to receive said electrical triggering signals fromsaid cycle controlling timing device, including electrical timersconnected severally to the several valve means, each of said timersbeing operative upon initiation of one only of said triggering signalsto produce first and second control signals spaced by a predetermineddelay interval, said apparatus including means actuating and maintainingactuated the several valve means in response to the several firstcontrol signals and deactuating the several valve means in response tothe seveRal second control signals, so that the amount of each liquidproduct supplied to said machine as a result of a triggering signal is afunction of the duration of the predetermined time delay interval,regardless of further continuance of said triggering signal; and h.means in each electrical timer for precisely adjusting the duration ofthe predetermined delay interval thereof.